Gain Staging and Gain Structure

As a broadcast engineer I frequently work with professional radio hosts who’ve been trained on proper leveling of equipment chains. They pretty much need this skill for job security as stations are broadcasted to hundreds of thousands and the show needs to sound good. But to be honest it hurts to go out and watch live shows of underground and local bands and DJs. It’s very common that their sound set up destroys the very music they’re wishing to play, plummeting quality and creating a loud mess. Due to the nature of the room acoustics the performers can’t even realize this without outside help.

The main culprit I’m talking about is audio distortion and it’s main cause in the live music scene is audio clipping from improper gain setup.

Gain is the amount of amplification of an audio signal. In a perfect world it’s a 1 to 1 ratio and the whole signal gets boosted uniformly and without issue. The problem is equipment has limits to what it can do. The peaks of signals can often be amplified until the point where the system no longer registers them. It’s just “Loud” and no longer notes. The most important thing to note with this is it happens with all gear. This isn’t just a software problem. It happens with mixers, audio interfaces, and sound systems. Here’s a quick video showing the effect on an audio editor:

With this in mind we can see how improper gain management can ruin the quality of a show, and we won’t know how bad it is until it’s playing. Even worse is it provides strain and starts to damage and weaken your equipment. So you have to follow some guidelines to determine how to properly set up the gain in your system. With proper organization and planning you can create a setup that not only removes this issue entirely but is extremely easy to adjust, even with multiple pieces of gear!

So here we go, how do I fix gain matching problems and how do I gain stage? Easy! The first thing you need to do is stop clipping on all your gear. If you have lights showing levels on your EQ meter you’ll immediately have a visual representation of the problem. Just adjust the volume/gain so you’re no longer maxing out. The last level should always flicker at the most. This prevents you from distorting the audio with this piece of equipment. Never go past this point and your audio will be fine. Now if you want to gain stage and you have multiple pieces of gear the best thing to do is max (without clipping) all of your equipment except for your last piece of gear that can set gain. This way you can easily adjust volume levels with just one piece of equipment. The rest of the gear in the chain is outputting the most it can without audio distortion and the last control will adjust the total volume output from the system.